Pipes may be used for transporting fluids, gasses or other medium from one location to another location. An end face of a pipe may be coupled to an end face of another pipe so as to extend the pipe length, for instance when a fluid or gas needs to be transported over a distance longer than the length of one pipe. Further, an end face of a pipe may also be connected to e.g. a container such as for instance a fuel tank, or any other device, such as a pump, which may provide the medium to the pipe, or to a T-connection. A system comprising at least one pipe connected to e.g. another pipe, a container, or any other suitable device, will in the following be referred to as a piping system.
A pipe coupling in a piping system should provide a robust, non-leaking connection in so that the medium stays within the piping system without leakage, even if the pipe coupling is subject to constant external forces. To this end, an arrangement of two flanges facing and fastened to each other may be utilised at a coupling interface between e.g. two pipes. Each flange typically has a plurality of axial through holes so that bolts may be fasted between the flanges when the end faces have been aligned.
One example of such a device is shown in U.S. Pat. No. 3,968,552, which discloses a method and apparatus for forming a plastic lined junction in a lined pipe. The apparatus comprises a ring fitted within a groove provided in the pipe, and a flange having a shoulder for mating with the ring when the flange is fitted around the ring.
Drawbacks with the above described apparatus are that the junction may become the weakest link in a piping system, both capacity-wise e.g. the apparatus may become a bottleneck, and with regards to robustness. Hence, improvements are needed to overcome the above drawbacks.